Quantification of Systematic Error in Standard Formula for Computing Transverse Relaxation Rates in DSCMRI. Implications for Blood Volume and Flow Calculations

Jos Rufino Solera Urea¹, Salvador Olmos¹

In dynamic susceptibility contrast (DSC) MRI experiments, the increase in the tissue transverse relaxation rate due to the passage of a bolus of intravascular paramagnetic contrast agent is routinely calculated (up to a constant) as the logarithm of the tracer dependent MR intensity normalised to baseline intensity, assuming that T1 effects are negligible. This assumption is revisited by developing the enhancement condition for a typical GE pulse sequence and the associated enhancement angle. The systematic error associated with the usual formula is analysed. Error expressions for the blood volume and flow calculations in DSCMRI experiments are also presented and their implications discussed.